1. Field of the Invention
The present invention relates to a pulse wave analyzing device that enables to measure parameters relating to a pulse wave of a living body and to provide a broad-ranging analysis concerning obtained measurement data so as to acquire findings on different cases concerning diseases (hereinafter, simply called as “cases”).
2. Description of the Related Art
There are known, for instance, a pulse oximeter, a polysomnography (PSG), and a holter monitor, as examples of a vital information measuring device for non-invasively detecting vital information concerning a living body such as a human body. The pulse oximeter is primarily used for diagnosing a sleep apnea syndrome (SAS), and is adapted to obtain a time-based change in blood oxygen saturation (SpO2) based on a two-wavelength pulse oximetry, which is conducted by: removably attaching a probe provided with a light emitter of emitting light of two different wavelengths and a light detector onto a finger of a subject; projecting light from the light emitter onto a living body i.e. the finger of the subject; and detecting a change in the amount of light transmitted through the living body. The PSG is a measuring device used in diagnosing SAS, as well as the pulse oximeter. The PSG is provided with sensor sections for detecting assessment parameters such as an electroencephalogram, an air flow rate through mouth or nose, snoring sounds, body positions/body movements, chest and abdominal movements in respiration, and electrocardiographic waveform, in addition to the SpO2, to analyze and display the measurement results. The holter monitor is a measuring device for diagnosing an arrhythmia or an atrial fibrillation. The holter monitor is provided with electrodes for detecting a cardiac activity potential, and is adapted to obtain electrocardiogram RR-intervals by analyzing an electrocardiographic waveform.
There is also known a portable vital information monitoring device capable of monitoring vital information without the need of replacing the device during sleep and during waking hours. The portable vital information monitoring device detects vital information which reflects pulsations, body movements, and an autonomic nervous system of a subject to constantly monitor vital information concerning the subject based on an assessment index during sleep and an assessment index during waking hours.
The conventional vital information measuring devices such as the pulse oximeter, the PSG, and the holter monitor are operated in such a manner that measurement data obtained by a measuring operation is temporarily stored in a memory section provided in the vital information measuring devices, and then, the measuring devices are connected to a personal computer with an analysis software or a like device to read the measurement data out of the memory section for data analysis. With use of the conventional measuring devices, the subject cannot be promptly informed of an analysis result concerning a case. Even with use of a measuring device easily measurable at home, the subject is requested to bring the measuring device to a medical institute after the measurement for data analysis to know his or her health condition, which is inconvenient.
Also, use of the conventional measuring devices is changed depending on cases in such a manner that the pulse oximeter or the PSG is used for a subject with a suspected sleep disorder, and a holter monitor is used for a subject with a suspected circulatory system disease such as an arrhythmia. Accordingly, if a subject has both symptoms related to a sleep disorder and a circulatory system disease, it is extremely difficult to find a symptom on the circulatory system disease based on measurement data obtained by the pulse oximeter, for instance. The portable vital information monitoring device is operable to change a measurement mode or an analysis timing depending on a judgment as to whether a body movement has been detected. However, the portable vital information monitoring device is a measuring device based on a premise that data concerning body movements be acquired, and is not a measuring device capable of providing a broad-ranging analysis on cases solely based on pulse wave data.